Automation's Untapped Gold Mine
by Carl Traynor
, Director of Marketing
Motoman Robotics Posted 08/23/2001
Use of Simulation Software to Improve 'Design to Manufacture'
Robotic simulation software has become a valuable tool used to perform a variety of time- and cost-saving tasks - from robot reach studies, up to and including off-line programming of robot cells - but simulation offers additional resources that we've only begun to tap.
In fact, off-line programming is often promoted as the 'silver bullet' that can minimize, if not eliminate, cost and time required to program robotic cells manually. As a result of this focus on off-line programming, the benefits of simulation traditionally have been viewed as a one-way transformation of CAD designs in the engineering office to production robot programs on the plant floor.
Savvy manufacturers are beginning to realize that simulation tools can also be used effectively in the other direction - using cycle time and process information from the plant floor to modify product designs, thereby maximizing their 'manufacturability' with existing automation tools.
In the current economic environment, the ability to re-use existing automation equipment to produce new products is more valuable than ever. Some manufacturers are now beginning to tap the power of simulation tools for nontraditional uses.
Originally, simulation tools were more widely used to perform 'reach studies' (i.e. to optimize robot placement before expensive tooling was fabricated). As part of a reach study, simulation verifies that a particular robot and end-of-arm tool can reach all of the positions required to complete a particular task and that the robot and tool will not collide with fixtures or other objects.
Prior to use of computer simulation, layout and reach studies were calculation-intensive tasks that required tremendous amounts of engineering hours. Manual calculations made multiple design iterations and workcell layout scenarios difficult, time-consuming, and cost-prohibitive. Additionally, even a small calculation error could be disastrous. Even if a reach study is performed correctly, because of its static nature, there is no guarantee that the robot system will achieve the desired cycle time/throughput.
So, as computing platforms have become more powerful, robot manufacturers have integrated actual robot motion planning within their own simulation software. As a result, customers are now able to predict and verify cycle time before a robot cell is assembled using dynamic computer simulation tools.
Off-line programming of robotic cells - i.e. generation of production robot programs using CAD data - was a natural next step in the use of simulation software. However, the same tools that make off-line programming possible and effective also add value to the process of design-to-manufacture.
If simulation software is not used, a customer who plans to launch production of a new product using an existing robotic cell might introduce changes to the product design that simply cannot be manufactured using the existing robot cell. Even now, the general approach to resolving this issue is to make changes in the layout and configuration of the robot cell. Unfortunately, such modifications might not be possible - particularly as manufacturers work to achieve 'rolling' changeovers rather than shutting down production lines.
Simulation software can allow design engineers to evaluate several designs - all of which can be produced on a particular robotic cell given some modification of the robot's programming. Part surface geometry dictates the path that the robot must take. Therefore, if the designer can simplify the part geometry to some degree, it might be possible to simplify the robot path, thus allowing faster cycle time. Robotic simulation tools allow the designer to quantify the amount of timesavings gained based on each change to surface geometry. Members of marketing and design teams can then select an optimum design for a new product, knowing its related throughput and accurate manufacturing cost - well ahead of the launch date.
With this new perspective on the use of simulation software, manufacturing customers can discover new 'gold': opportunities to maximize the return on their investment in flexible, robotic automation tools.